Rdio, a new startup from Skype/Kazaa/Joost founders Janus Friis and Niklas Zennstrom has already created quite a stir, namely because of its pedigree.

The service will let users share and archive music through a browser and stream it to mobile devices.

Supposedly still in stealth mode, the startup is yet to officially open for business, yet the team at Music Ally have already spotted its iPhone app available for download via the app store.

Here’s the description:

“Rdio is like carrying a giant MP3 player in your pocket – you have unlimited and unrestricted access to all the music, and you get to select exactly the song, album or artist you want to hear. And you can skip, pause fast forward as much as you want. Build your collection and compose your playlists on rdio.com and listen to them all on the go. Or search for just the right song when you’re out and it will start playing instantly.”

Sounds a lot like Spotify doesn’t it?

We can only assume the app is available for its current private beta users, but if you’d like to have it sitting pretty until you have access you can download the app for free here.